add mima plugin

Author: pjfanning

build.sbt

@@ -9,6 +9,8 @@ scalaVersion := "2.13.4"
 
 crossScalaVersions := Seq("2.11.12", "2.12.13", "2.13.4")
 
+mimaPreviousArtifacts := Set(organization.value %% name.value % "2.12.1")
+
 resolvers += Resolver.sonatypeRepo("snapshots")
 
 val scalaMajorVersion = SettingKey[Int]("scalaMajorVersion")

project/plugins.sbt

@@ -16,3 +16,5 @@ addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "5.2.4")
 addSbtPlugin("com.typesafe.sbt" % "sbt-ghpages" % "0.6.3")
 
 addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.8")
+
+addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "0.8.1")